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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

The major constituents, phenol and 4,4’-isopropylidenediphenol (representing 60-85% of the composition), have been shown to meet criteria for classification as readily biodegradable.  Biodegradation of the impurities in the substance was assessed using both QSAR estimation and experimental methods.  The components are predicted to biodegrade slowly and at varying rates, which is consistent with 16% biodegradation observed in screening tests after 28 days.  Overall, the substance (reaction mass of phenol and 4,4’-isopropylidenediphenol) would be expected to ultimately biodegrade in the environment.

Key value for chemical safety assessment

Biodegradation in water:
inherently biodegradable

Additional information

The environmental properties of the reaction mass of phenol and 4,4’-isopropylidenediphenol was assessed by examination of the properties of the constituents and impurities of the mixture and using this information in a read across approach as described in section 13. 

 

The major constituents of the reaction mass, namely phenol and 4,4’-isopropylidenediphenol (representing 60-85% of the composition) have been shown to meet criteria for classification as readily biodegradable. Phenol showed 62% biodegradation within 100 hours in the OECD 301C screening test. Extensive biodegradation (86-96%) was also noted for phenol in biochemical oxygen demand tests conducted with both freshwater and saltwater inocula. 4,4’-Isopropylidenediphenol has also shown to be extensively degraded in OECD 301F manometric respirometry tests. The extent of degradation ranged from 77 to 92.3% and 76 to 81% based on oxygen consumption and CO2 formation, respectively.

 

Biodegradation of the impurities in the substance was assessed using both QSAR estimation and experimental methods. Screening tests were conducted according to OECD 301F with a test material, 2-Acetone, polymer with Phenol, which is a suitable surrogate for the reaction mass of phenol and 4,4’-isopropylidenediphenol. The results showed 16% biodegradation after 28 days, although biodegradation may have been limited by availability of the components to the microorganisms. QSAR model predictions indicate the various minor constituents of the reaction mass are expected to biodegrade slowly and at varying rates, ranging from weeks to months. Overall, the substance (reaction mass of phenol and 4,4’-isopropylidenediphenol) would be expected to ultimately biodegrade in the environment.